將DataSet更改保存到MYSQL數據庫表的問題

Question

我使用來自表A的數據填充dataGridView，該數據屬於MySQL數據庫表。在插入新數據或修改DataTable A的數據後調用SaveChangestoDb(string TableName)方法時 - 將更改保存到數據庫，但是當我將表A中批准的DataRows轉移到表B時，然後從表A中刪除批准的行...保存對錶A所做的更改失敗。它不會拋出任何例外。

我使用BindingSource將表A綁定到dataGridView和CommandBuilder以獲取有關DataAdapter的更新。

這裏是我的代碼：

private const string ConnectionString = 
     "server=*****.**;Port=****;database=**;username=****;password=*****;pooling=false;"; 

    private DataSet _localDatabaseCopy; 
    private MySqlDataAdapter _myDataAdapter; 

    private void Form1_Load(object sender, System.EventArgs e) 
    { 
     InitializeLocalDatabaseCopy(); 
     InitializeDataGridView(); 
     dataGridView1.AllowUserToAddRows = false; 
    } 

    /// <summary> 
    /// Binds the DataGridView to the BindingSource and load the data from the database. 
    /// </summary> 

    private void InitializeDataGridView() 
    { 
     DataTable dataTable = _localDatabaseCopy.Tables[Resources.WorkingDataDatabaseTableName]; 
     dataGridView1.DataSource = new BindingSource { DataSource = dataTable }; 
     dataGridView1.MultiSelect = true; 
     dataTable.Columns[Resources.ColumnName_IDNr].AutoIncrement = true; 
     dataTable.Columns[Resources.ColumnName_IDNr].AutoIncrementSeed = -1; 
     dataTable.Columns[Resources.ColumnName_IDNr].AutoIncrementStep = -1; 


    } 
    /// <summary> 
    /// Fills the _myDataAdapter DataAdapter with the workingData & approvedData DataTables and adds the 2 DataTables to the _localDatabaseCopy DataSet. 
    /// </summary> 
    private void InitializeLocalDatabaseCopy() 
    { 
     _localDatabaseCopy = new DataSet(); 
     DataTable workingData = new DataTable(Resources.WorkingDataDatabaseTableName); 
     DataTable approvedData = new DataTable(Resources.ApprovedDataDatabaseTableName); 
     using (MySqlConnection connection = new MySqlConnection(ConnectionString)) 
     { 
      _myDataAdapter = new MySqlDataAdapter(string.Format("select * from {0}", Resources.WorkingDataDatabaseTableName), connection); 
      _myDataAdapter.Fill(workingData); 
      _myDataAdapter.SelectCommand.CommandText = string.Format("select * from {0}", Resources.ApprovedDataDatabaseTableName); 
      _myDataAdapter.Fill(approvedData); 
     } 

     _localDatabaseCopy.Tables.Add(workingData); 
     _localDatabaseCopy.Tables.Add(approvedData); 
    } 



    private void SaveChangesToDb(string tableName) 
    { 
     MySqlCommandBuilder builder = new MySqlCommandBuilder(_myDataAdapter); 

     _myDataAdapter.SelectCommand.CommandText = String.Format("select * from {0}", tableName); 
     _myDataAdapter.UpdateCommand = builder.GetUpdateCommand(); 
     _myDataAdapter.DeleteCommand = builder.GetDeleteCommand(); 
     _myDataAdapter.InsertCommand = builder.GetInsertCommand(); 

     DataTable deletedRecords = _localDatabaseCopy.Tables[tableName].GetChanges(DataRowState.Deleted); 
     DataTable modifiedRecords = _localDatabaseCopy.Tables[tableName].GetChanges(DataRowState.Modified); 
     DataTable addedRecords = _localDatabaseCopy.Tables[tableName].GetChanges(DataRowState.Added); 
     try 
     { 
      if (deletedRecords != null) 
       _myDataAdapter.Update(deletedRecords); 
      if (modifiedRecords != null) 
       _myDataAdapter.Update(modifiedRecords); 
      if (addedRecords != null) 
       _myDataAdapter.Update(addedRecords); 

      _localDatabaseCopy.AcceptChanges(); 

     } 
     catch (Exception exception) 
     { 
      MessageBox.Show(exception.Message); 
     } 
     finally 
     { 
      if (deletedRecords != null) 
       deletedRecords.Dispose(); 
      if (modifiedRecords != null) 
       modifiedRecords.Dispose(); 
      if (addedRecords != null) 
       addedRecords.Dispose(); 
     } 

    } 



    private void btnSave_Click(object sender, EventArgs e) 
    { 

     SaveChangesToDb(Resources.WorkingDataDatabaseTableName); 

    } 


    private void DeleteDataRows(DataRow[] rowsToDelete, string tableIndex) 
    { 
     foreach (DataRow row in rowsToDelete) 
      _localDatabaseCopy.Tables[tableIndex].Rows.Remove(row); 
    } 


    /// <summary> 
    /// Transfers the approved DataRows from the DataTable/DataGridview to the Approved Table in the MySql Database 
    /// </summary> 
    /// <param name="sender"></param> 
    /// <param name="e"></param> 
    private void btnTransferApproved_Click(object sender, EventArgs e) 
    { 
     SetWaitingCursor(); 

     TransferApprovedDataRows(); 
     DeleteTransferedRowsFromWorkingDataTable(); 
     SaveChangesToDb(Resources.WorkingDataDatabaseTableName); 

     SetDefaultCursor(); 
    } 

    private void DeleteTransferedRowsFromWorkingDataTable() 
    { 
     DataRow[] approvedRowsToDelete = _localDatabaseCopy.Tables[Resources.WorkingDataDatabaseTableName].Select("Approved = 1"); 
     DeleteDataRows(approvedRowsToDelete, Resources.WorkingDataDatabaseTableName); 

    } 

    private void TransferApprovedDataRows() 
    { 
     DataTable myTableCopy = _localDatabaseCopy.Tables[Resources.WorkingDataDatabaseTableName].Copy(); 
     DataRow[] approvedRows = myTableCopy.Select("Approved = 1"); 

     // if there are no rows which have been approved, quit 
     if (approvedRows.Any()) 
     { 
      foreach (DataRow row in approvedRows) 
      { 
       // checking if the row which is to be approved already exists in the approved-table 
       bool redundant = false; 
       foreach (
        DataRow approvedRow in _localDatabaseCopy.Tables[Resources.ApprovedDataDatabaseTableName].Rows) 
        redundant |= approvedRow[Resources.ColumnName_IDNr].ToString() == 
           row[Resources.ColumnName_IDNr].ToString(); 

       if (!redundant) 
        _localDatabaseCopy.Tables[Resources.ApprovedDataDatabaseTableName].Rows.Add(row.ItemArray); 
      } 
      // writing the changes back to the database, Approved Table 
      SaveChangesToDb(Resources.ApprovedDataDatabaseTableName); 
     } 

     if (!approvedRows.Any()) 
      return; 


    } 


} 

}

Answer 1

的問題是在你的DeleteDataRows方法。從表格中刪除行不會將它們標記爲刪除，只是將它們從表格的內存中表示中刪除。你需要調用DataRow.Delete：

private void DeleteDataRows(DataRow[] rowsToDelete, string tableIndex) 
{ 
    foreach (DataRow row in rowsToDelete) 
     row.Delete(); 
}